Method of making moldable material



I0 Drawing.

Patented Nov. 10, 1931 UNITED STATES PATENT OFFICE LOUIS '1. FREDERICK, 0F VALPARAISO, INDIANA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CONTINENTAL DIAMOND FIBRE COMPANY, OF NEWARK, DELAWARE, A 0015- PORATION OF DELAWARE METHOD OF MAKING MOLDABLE MA'ImIAL My invention relates to methods of making moldable material 'of the typeused by laminators and others and consisting of small pieces of fabric impregnated with a phenohc condensation product or similar thermoplastic binder.

One of the objects of my inventlon is to reduce the amount of labor involved in the process of producing this class of material, and another object is to reduce the cost of the raw material, at least as to the fabric, by making it possible to utilize small scraps constituting thewaste products of other industries, e. g. scraps of duck-or canvas resulting from the shoemaking industry, also the manufacture of tents and awnings, boat sails, etc.

One of the methods now known for pro ducing such moldable material is to take scraps of the type mentioned and place them in a vat containing a solution of a suitable heat curable binder which preferably comprises an unreacted phenolic condensation product which is sometimes known as synthetic resin. After the scraps are saturated they are taken out and drained then dried and finally chopped up or shredded until the desired degree of fineness is attained. .But this method has a disadvantage in that the scraps tend to wad or clot together and this fact coupled with the drainage operation tends to distribute the solution unevenly. Furthermore the particles stick together and have to be separated, which is an added operation.

Another known method is to take sheets or strips of duck or other fabric and pass them through a bath of the unreacted solution and then cut or chop up the material. But this, while it obtains uniform distribution, is too expensive as it calls for sheet material as distinguished from scraps.

According to my method it is possible to utilize scraps and at the same time it obtains uniform distribution and eliminates the step, as a separate operation, of separating the dried particles. It also avoids the use of an excessive amount of the solution, that is, the over-saturating of the particles and the subsequent drainage. Moreover, it will be understood that the solvents usually employed, i. e., alcohol or acetone, are expensive and Application filed August 13, 1927. Serial No. 212,827.

volatile and a certain amount of evaporation during draining is unavoidable except by the use of special recovery apparatus.

In my process I take the scraps just as they arrive from the shoe factories, tent and awning makers, clothing makers and other producers of such scraps and cut or chop them into the sizes of particles ultimately desired. These usually vary from pieces the size of a dime to pieces the size of a quarter or larger and may be, of course, of irregular shape. As this cutting or chopping is done while the scraps are free of the resin it is accomplished more readily and with less wear on the knives than otherwise. Also there is little or no tendency to produce very fine particles or dust as is often the case when the particles are chopped up after impregnating and drying. Then when the particles have thus been prepared, I measure out a definite quantity of the resin solution, that is, the exact amount required for a given Weight of scraps. Thus, I do not depend on the exigencies of draining, for in draining, the amount retained cannot be exactly controlled as it depends upon the size of the particles, the size or weight of the pile in. which they are drained, the percentage of solvent in the solution and the time allowed for drainage.

In my process, after the untreated scraps have been cut up and the quantity of solution selected the Whole is placed in a container in which the mass may be agitated. In practice I use a dough mixing machine of any suitable type, such machines being well known.

After the machine has been operated for a reasonable period (which will vary with conditions) it will be found that the solvent will have evaporated and the resin itself will have been thoroughly distributed over the particles. Furthermore, it will be found that the particles are all fully separated from each other. Another fact will also be discovered and that is that the particles or most of them are flat. This is of real importance and not always found in the other processes. The advantage is that the particles when placed in the mold will be flatwise and thus produce better uniformity in the finished article than when some of the particles are more or less curled up and a certain amount of fines or dust is present. Uniformity in 5 the resulting article, is important, for example in the web of a gear, and as a result of the production of fiat particles in my proc ess, better gears are to be produced.

From the foregoing it will be evident that my process results in important economies in time and material and produces a uniform product of controllable consistency and that the particles are fiat, which is the condition most desirable in material of this kind.

While I have mentioned woven fabric as.

the material from which the moldable material is to be made, untreated paper is another fabric which may be employed.

. Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. The method of making moldable mate rial which consists in reducing untreated fabric to ultimate desired size and then mixing with the particles a solution of a suitable heat curable binder and evaporating the solventwhile agitating the mixture whereby the fabric particles may be evenly impregnated with the binder to produce a moldable material.

2. The method 'of making moldable material, which consists of conflningfibrous scraps with a measured quantity of a suitable binder dissolved in a volatile solvent and agitating the mass while the solvent is evaporated.

3. The method of making an amorphous moldable material, which consists in reducing untreated fibrous material to ultimate desired size, mixing the sized particles with 40 a solution of a suitable heat curable binder and finally evaporating the binder solvent while agitating the mixture whereby to produce a uniformly impregnated amorphous molding material.

In witness whereof, I have hereunto subscribed my name.

LOUIS T. FREDERICK. 

